The invention relates to communication networks, and, more particularly, to secure mechanisms for enabling seamless mobility in wireless communication networks.
Wireless communication networks permit a user of a mobile terminal to roam geographically typically through the notion of a “hand-off” in which a communication link is transferred from one access point/base station to another. Recently, standards have been developed for integrating mobility support into packet-switched networks, such as Internet Protocol (IP)-based networks, including the notion of an IP-level handoff between access routers (ARs) which act as points of attachment to an IP network. See C. Perkins, ed., “IP Mobility Support,” Internet Engineering Task Force (IETF), Request for Comments 2002, October 1996, which is incorporated by reference herein. Unfortunately, the handoff latency and packet loss incurred can be too high for many scenarios, especially those that require a high level of quality of service (QoS). Recent developments have introduced low-latency handoff mechanisms that can reduce handoff latency significantly. See G. Mommety, A. Yegin, C. Perkins, G. Tsirtsis, K. El-Malki, M. Khalil, “Fast Handoffs for Mobile IPv6, ” IETF, Internet Draft, draft-ietf-mobileip-fast-mipv6-04.txt, work in progress, March 2002, which is incorporated by reference herein. However, such low-latency handoff mechanisms typically require some a priori knowledge of the target of the handoff, the next access router, including the IP address of the router.
Protocols have been developed that permit the discovery of geographically adjacent routers and that enable the collection of information regarding such “candidate” access routers prior to a handoff situation. See E. Shim, R. D. Gitlin, “Fast Handoff Using Neighbor Information,” IETF, Mobile IP Working Group, Internet Draft, draft-shim-mobileip-neighbor-00.txt, November 2000; D. Trossen, G. Krishnamurthi, H. Chaskar, E. Shim, R. D. Gitlin, “Protocol for Candidate Access Router Discovery for Seamless IP-level Handovers,” IETF, SeaMoby Working Group, Internet Draft, draft-trossen-seamoby-cardiscovery-00.txt, work in progress, November 2001; and D. Funato, X. He, C. Williams, A. Takeshita, “Geographically Adjacent Access Router Discovery Protocol,” IETF, SeaMoby Working Group, Internet Draft, draft-funato-seamoby-gaard-00.txt, work in progress, November 2001, the contents of which are incorporated by reference herein. Unfortunately, the inventors have recognized that existing protocols have serious security problems and can be susceptible to a number of different security threats.
Accordingly, there is a need for more secure mechanisms for enabling the dynamic collection of information about neighboring access nodes, which account for the possibility of untrusted mobile terminals and access nodes.